Ionization potentials and structural properties of finite-length single-walled carbon nanotubes: DFT study

•We calculated vertical and adiabatic ionization potentials for a series of SWCNTs.•The SWCNTs aromaticity influence on ionization potentials was observed.•We examine changes in the structure of SWCNTs upon ionization.

Adiabatic and vertical ionization potentials (IPs) of single-walled carbon nanotubes (SWCNTs) as a function of length were determined by using density functional theory. The correlation between periodic oscillations of SWCNTs local aromaticity and the values of IPs was founded. In the case of short SWCNTs an appreciable gap between vertical and adiabatic IPs was observed, whereas for longer nanotubes these values are almost equal. It was also established that the HOMO electron density distribution in neutral SWCNTs affects on SWCNT lengths upon ionization.